28722506 has 4 divisors (see below), whose sum is σ = 43083762. Its totient is φ = 14361252.

The previous prime is 28722479. The next prime is 28722517. The reversal of 28722506 is 60522782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60522782 = 2 ⋅30261391.

It can be written as a sum of positive squares in only one way, i.e., 21077281 + 7645225 = 4591^2 + 2765^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7180625 + ... + 7180628.

Almost surely, 2^28722506 is an apocalyptic number.

28722506 is a deficient number, since it is larger than the sum of its proper divisors (14361256).

28722506 is a wasteful number, since it uses less digits than its factorization.

28722506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14361255.

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 28722506 is about 5359.3382054131. The cubic root of 28722506 is about 306.2485982998.

The spelling of 28722506 in words is "twenty-eight million, seven hundred twenty-two thousand, five hundred six".